<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>检测是否是数字，包括整数，小数</title>
</head>
<body>
    <script>
        function testReg() {
            var str = prompt("请输入一个数字");
            if (/^-?\d+(\.\d+)?$/.test(str)) {
            
               alert("输入正确，是数字");
            } else{
               alert("输入错误，非数字");
            }
        }
        testReg();
    </script>
</body>
</html>